Carburetor



Sept. 15, 1936. H. v. CROON V 2,054,363

CARBURETOR Filed Sept. 4, 1929 2 Sheets-Sheet l fierman 6. 670072.

Sept. 15, 1936. H. v. CROON 2,054,363

CARBURETOR Filed Sept. 4, 1929 2 Sheets-Sheet 2 Patented Sept. 15, 1936 UNITED STATES CARBURETOR Herman v. Croon, Chicago, Ill., assignor to Marvel Carbureter Company, Flint, Mich., a corporation of Illinois Application September 4, 1929, Serial No. 390,290

17 Claims.

My invention relates to carburetors and more particularly to a throttle controlled carburetor with an accelerating and decelerating fuel pumping device.

An object of my invention is to provide a carburetor which is better able to meet the different fuel demands of. an internal combustion engine than the conventional carburetor.

Another object of my invention is to provide a carburetor with an improved accelerating pumping device.

A further object of my invention is to provide a throttle controlled carburetor with an accelerating and decelerating fuel pumping device.

A still further object of the invention is to provide an accelerating device for use with a throttle controlled carburetor arranged to discharge an extra supply of fuel directly into the high speed jet of the carburetor when the throttle is opened suddenly and adapted upon a quick subsequent closing of the throttle to give a decelerating effect by stopping the flow of fuel through the high speed jet.

In accordance with the general features of my invention there is provided an accelerating device for use in connection with a throttle controlled carburetor which device comprises fuel pumping means including a spring urged piston positioned in a pump cylinder and slidably disposed on a guide rod operable by the throttle valve; the discharge of the cylinder being connected directly to the high speed jet of the carburetor.

Other objects and features of my invention will more fully appear from the following detailed description taken in connection with the accompanying drawings which illustrate several embodiments thereof and in which:

Figure 1 is a plan view of a throttle carburetor provided with my novel accelerating and decelerating device;

Figure 2 is a sectional view taken on substantially the line II-II of Figure 1 looking in the direction indicated by the arrows and showing clearly the construction of the pumping device;

Figure 3 is a sectional view partly in elevation taken on substantially the line IIII]I of Figure 1 looking in the direction indicated by the arrows and illustrating the construction of the float chamber;

Figure 4 is a vertical sectional view similar to Figure 2 through a modified form of carburetor of my invention as shown on the drawings; and

Figure 5 is an enlarged fragmentary view of v the pump mechanism as shown in Figure 2.

As shown on the drawings;

Positioned in a heating receptacle ID are a pair of float chambers II and I2 which are formed in a single metal casting l3 having a flange portion H for resting on the top edge of the receptacle [0. A cover plate l5 extends over the top of the chambers II and I2 and over the flange portion II. This cover may be secured to the casting I! by means of screwsvor bolts l6 which extend through the flange portion I 4 into the sides of the receptacle or box "I.

It will be noted from Figures 2 and 3 that the bottom of the casting l3 as well as the walls thereof are spaced from the bottom and walls respectively of the receptacle I through which a suitable heating medium is adapted to flow. The ends of the receptacle Ill are provided with pas sageways l1 and I8 which may be suitably connected to a heating system. For example, if the carburetor of my invention is used in connection with the internal combustion engine of an automobile, one of the passageways ll-IB may be connected to the exhaust manifold of the engine and the other passageway may be connected to the mufller so that the heat of the exhaust gases may be utilized to vaporize the fuel 20 in the chambers II and I 2.

In Figure 2 it will be observed that the casting I3 is provided with an intermediate recess 2| disposed between the flow chambers and adapted to allow the heating medium to flow upwardly between the chambers to augment the vaporization of the gas or fuel in these chambers.

Fastened to the top of the cover plate l are two tubes 22 and 23 disposed in communication with openings 24 and 25 respectively in the cover plate l5. The tube 22 is connected to a horizontal mixture outlet passageway 26 adapted to be connected to the intake manifold in the usual way of an internal combustion engine and having disposed in it conventional throttle and choke valves 21 and 28. The tube 22 establishes communication between the float chamber l l and a portion of the passageway or mixture chamber 26 between the throttle valve 21 and the intake manifold of the engine.

Pivotally disposed in the two float chambers II and [2 are the floats 3| and 32 secured to arms 33 and 34 respectively hingedly connected to brackets 35 and 36 fastened to the wall of the casting l3. Each of the supporting arms 333l includes a turned back portion upon which is supported a needle valve member 31-38 which extends through tubular plugs 394ll threadingly secured to the cover plate l5. Each of the needle valve members is adapted to cooperate with a 81 and 88 a fuel supply pipe line 45 extending in a direction toward the mixture passageway 28.

From the block 43 the pipe 45 extends to a hollow block 48 having downwardly threaded reduce portion 41 threaded into an opening in the mixture passageway 28 directly over the throttle valve 21. The tubular portion 41 is provided acentral opening 48 cooperable with a needle valve member 48 threaded into the top of the block 48 and provided with a thumb wheel 58 by which it may be adjusted. Obviously, by adjusting the position of the valve member 48 with respect to the opening 48 it is possible to vary the amount of fuel allowed to enter the opening 48.

The block 45 is provided with a threaded extension 5| (Figure 1) by which the pipe line 45 may be connected to the fuel line leading to the supply tank or other source of fuel.

The throttle valve 21 is connected to a shaft 55 extending clear through the mixture passageway 28 and having mounted on an outer end (Figure l) a lever arm 58 pivotally connected to an end of a transverse link 51 the other end of which is pivotally connected to the free end of a lever arm 58 secured to shaft 58 extending through the mixture passageway 28 and suitably Joumalled therein. Fastened to the free end of this shaft 58 is an arm 88 which may be connected in the usual way to the throttle or the accelerator at the driver's station of the automobile or the like.

The choke valve 28 is also secured to a shaft 8| extending through the mixture passageway 28 and suitably journalled therein. The outer and free end of this shaft 8| may be connected in the usuahway to the choke on the dash of the automotive vehicle.

I shall now proceed to describe in detail my novel accelerating and decelerating pumping mechanism. Secured to an intermediate portion of the shaft 58 inside of the mixture passageway 28 is a cam 85 which projectsthrough a slit or recess 88 in the tube 28. This tube 28 extends through an opening 81 in an enlarged portion 88 of the mixture passageway 28 (Figure 2).

The cam 85 is arranged to engage the head 18 on the upper end of a rod 1| extending downwardly through the opening 25 into the float chamber l2. The lower end of the rod 1| has formed integral with it a head 12 upon which is supported a piston 18 loosely mounted on the. The piston 18 is slidably disposed guide rod 1 I. within a cylinder 14 which has its lower end provided with a reduced threaded portion 15 threaded into the bottom of casting l3 at 18. This reduced portion 15 is provided with a frusto conical central opening 11 in which is disposed a ball valve member 18. The lower end of the opening 11 is disposed in communication with the float chamber l2 by means of a lateral passageway 18.

The upper part of the cylinder 14 is provided with a cap 88 suitably secured thereto provided with a central tubular portion 8| through which the guide rod 1| extends. Positioned between the cap 88 and the piston 18 is a compression spring 82 which surrounds the guide rod 1|. Also surrounding the guide rod 1| and positioned between the head 18 and the upper end of the tubular portion 8| is a spring 83 the purpose of which will be more fully explained hereinafter.

aosgscs The lower end of the cylinder 14 is provided with a lateral extension 85 in which is secured an upwardly extending pipe or tube comprising a high speed- Jet 88. The upper end of this jet is bent laterally toward the throttle valve as indicated at 81. The lower end of the tube 88 is disposed in communication with a fuel passageway 88 formed in the extension 85. The lower end of this passageway 88 is tapered so as to communicate with a smaller eway 8| and so as to form a seat for a ball valve 82 adapted to rest on this seat between the passageways 88 and 8|. The upward movement of the ball valve 82 is limited by a transverse pin 88 extending into the extension 85 and through the passageway 88. The lowermost end of the reduced passageway 8| is disposed in communication with the interior of cylinder 14 by means of a slot 85 (Figure 2).

The operation of my novel carburetor is briefly as follows.

Fuel is supplied to the float or vaporizing chambers II and i2 from the pipe." as a result of the subatmospheric pressure which prevails in the float chambers, and the amount of fuel allowed to enter these chambers is regulated by the float operated valve members 31 and 88. This arrangement is highly desirable for the reason that it eliminates the necessity of a vacuum tank or the like and enables fuel to be drawn directly from the source of supply which may be the fuel tank on an automobile by the suction of the engine acting on the gas in the float chambers. The fuel in the two chambers ii and I2 vaporizes readily due to it being submitted to a subatmospheric pressure andthis vaporization process is augmented by the heat imparted to the fuel in these chambers from the heatingmedium flowing through passageway Ill so that vapor is caused to rise from the surface of the fuel in the float chambers.

Upon the starting of the engine the choke valve 28 will be moved to a substantially closed position and the throttle valve 21 will be in substantially the position shown in Figure 2. The suction of the engine connected to the passageway. III will then function to draw fuel from the tubes 22 and 23 and from the jet or passageway 48. The purpose of the tube 22 is to supply fuel or gas vapor for the initial operation or starting of the engine.

It will, of course, be appreciated that when the throttle valve is in a substantially closed position such as that shown in Figure 2, the suction directly over the tube 22 and the opening 48 will be at a maximum so that fuel is drawn from both of these points into the mixing passageway 28.

The jet passageway 48 serves to supply fuel for the engine during an idling operation but is rendered substantially ineffective to supply any substantial amounts of fuel to the passageway 28 when the throttle valve 21 is open due to the fact that the air will thenrush through the center of the passageway rather than follow the internal surface of the walls defining the passageway. In other words, the passageway 48 in reality is adapted to deliver a throttle controlled jet of fuel into the mixing chamber 28.

The tube 23 supplies gas vapor to the mixing chamber 28 for the operation of the engine at relatively low speeds. As the throttle of the engine is opened to increase the speed of the engine to an amount whereby the automobile can be operated at twenty or more miles an hour,- the high speed jet 88 comes into operation to deliver a charge of inder 14.

If the throttle should be moved suddenly from an idling position to a wide open position so as to immediately speed up the engine, the cam 65 forces the rod 83 downwardly within the cylinder I4 thereby allowing the spring 82 which is normally compressed to move the piston 13 downwardly in the cylinder thus forcing an extra Jet .or charge through the highspeed jet 86 into the mixing chamber 26. This extra charge of fuel augments the acceleration of the engine connected to the carburetor thus enabling the carburetor to promptly meet the demands of the engine. 7

n the other hand, if the throttle valve 21 should be moved suddenly from its wide open or high speed position to an idling or substantially closed position the piston I3 is moved upwardly so quickly within the cylinder I4 by the action of spring 83 which was compressed during the lowering of the piston as to create a vacuum in the cylinder greater than that acting upon the discharge end of the jet 86 whereby the ball valve Si is drawn down on its seat thus immediately cutting off the passage of further fuel into the jet 86. This action gives a decelerating effect since it enables the high speed jet 86 to be quickly rendered inoperative as far as delivering further fuel in the mixing chamber 26 is concerned.

It is to be noted that when the throttle valve 21 is opened slowly the cam 65 is moved downwardly slowly thus gradually lowering the piston I3 in the cylinder I4. Under such conditions the piston delivers little or no extra fuel into the jet 86 which is desirable for the reason that it has been found that when the throttle is gradually opened accelerating fuel is not only unnecessary but is apt to be a detriment to the smooth operation of the engine. Similarly when the throttle is gradually moved to a closed position the piston I3 is moved upwardly slowly within the cylinder 14 and hence does not create a great enough suction within the cylinder to draw the ball valve SI to its seat.

It will be noted that when the piston I3 is forced down quickly within the cylinder the ball valve I8 is quickly forced to its seat so as to trap a charge of fuel within the lower part of the cylinder. Due to the fact that the piston I3 is loosely mounted on the guide rod I I, the piston is free to move downwardly under the effects of the compressed spring 82 and hence independently of the rate of movement of the guide rod by the throttle valve. Then, too, since the piston is loosely mounted on the rod provision is thereby made for the venting of gas pressure from the lower part of the cylinder as the piston is moved downwardly. Also, gas pressure accumulating in the upper part of the cylinder is allowed to escape therefrom through the extension 6| around the guide rod which is loosely fitted therein.

In Figure 4 I have illustrated a modified form of carburetor embodying the features of my invention in which I employ a pivotally mounted pumping cylinder as I will more fully explain hereinafter. Positioned in a heating chamber I88 is a float chamber ml which chambers are formed in a single casting I82. Fastened to the top of the casting I82 is a cover plate I83 which has formed integral therewith an upwardly extending venturi I84 disposed in communication with the float chamber I8 I.

Positioned in the float chamber I8I is a float I85 secured to a U-shaped arm I86 pivotally secured to a bracket I81 fastened to the under side of the cover plate I83. The upper leg of this U- shaped element I86 is arranged to engage the lower end of a needle valve member I88 cooperable with the lower end of passageway I88 in plug I I8 threaded into the cover plate I83. The upper end of the passageway I83 communicates with the bore of a tube III having its lower end anchored to the top of plug I I8 by means of a cap I I2. The upper end of the tube III is anchored to a tubular plug II3 by means of a cap II4. The plug H3 is formed integral with a pipe II5 adapted to be connected directly to a source of fuel such, for example, as the gasoline tank on an automobile thereby eliminating the necessity of a vacuum tank or the like. This pipe II5 has formed integral with it a nozzle I I6 threaded into a hollow casting III which defines the outlet or mixing chamber II8 of the carburetor. The nozzle H6 is disposed in communication with the portion of the mixing chamber I I8 directly below the throttle valve I28 by means of idling jet passagewav I I6. This throttle valve I28 is secured to a shaft I2I journalled in and rotatably carried by the casting III.

The casting II'I comprises a hollow cylindrical tube I22 which defines a mixing chamber I I8 and an outer curved wall I23 spaced from the tube I22 so as to define an air circulating chamber I24. This air circulating chamber I24 is disposed in communication with an air passageway I25 formed in tube I26 which is integral with casting III. Disposed in the air passageway I25 is a choke valve I38 secured to a shaft I29 rotatably carried by the tube I26. The valve I38 may comprise a static or spring air control device. That is to say this valve may be a conventional spring urged valve having a spring adjusted to allow the valve to open in accordance with the suction prevailing in tube I22 and tube I26.

The air circulating chamber I24 is aligned with an annular space I3I formed by an annular depression I32 in the cover plate I83. Also it will be apparent that the venturi I84 extends up into the inside of tube I22. This arrangement allows any overflowing fuel to gravitate into the space I3I on top of the depression I32 where such fuel can be picked up by the air circulating in chamber I24 from the passageway I25. Obviously, in order for the air from the passageway I25 to enter the mixing chamber II8 it is necessary for such air to circulate through the spaces I24 and I3I over the top surface of the depression I32 and under the lower edge of the tube I22. During this circulation of the air being drawn into the intake manifold such air will of necessity pick drops of fuel accumulating on the depression I32 as the result of an overflow or the like.

The throttle valve I28 has secured to its under side an eye I35 to which is pivotally attached the upper end of a guide rod I36 having its lower end extending through an opening I3I in the top plate I38 of a pump cylinder I39 in which is disposed a movable piston I48. The piston I 48 is slidably and loosely mounted on the guide rod I36 and is adapted to be supported by a head I4I formed on the lower end of the guide rod I36 as shown on the drawings. Surrounding the guide rod I36 and disposed between the cap I38 and the piston I48 is a normally compressed spring I42 which when the throttle I28 is in the position shown in Figure 4 is adapted to urge the piston I48 in a direction toward the bottom of the cylinder I33.

The lower end of the cylinder I39 is provided with an extension I43 pivotally attached to the bracket I44 secured to the wall of float chamber gong-soam, This extension is provided with an enlarged m through the Jet no mm the mixing recess I45 communicating at its upper end with the interior of cylinder I99 and at its lower end with a reduced fuel passageway I49 through which the flow of fuel is controlled by a ball valve I41 arranged to seat in the upper end of the passageway I46. Upward movement of the ball is limited by a pin I49 extending into the recess I45. It will be evident from this description that fuel from the float chamber I M can pass through the passageway I46 into the interior of cylinder I99 by raising the ball I41 ofl its seat. However, whenever an excessive pressure is exerted upon the top side of the ball I41 it will result in this ball being forced to its seat thus shutting-oi! the flow of fuel into the interior of cylinder I99.

One side of the cylinder wall is enlarged as indicated at I49 and has rigidly fastened to it an upwardly extending high speed nozzle or jet I50 which has its upper end bent to terminate under the throttle valve I20 as indicated at I5I. The lower end of the jet I50 is disposed in communication with a vertical passageway I59 through which the flow of fuel from the interior of cylinder I39 is controlled by'means of a ball valve I54. Upward movement of the ball valve is limited by a pin I55 extending into the passageway. The lower end of the passageway I59 communicates with a recess I56 disposed in communication with the bottom of the chamber within cylinder- I99.

The operation of this modified form of carburetor is substantially like that of the preferred form previously described with the principal exception that a pivotal mounting is provided for the pump cylinder whereby the guide rod associated with the piston may be secured directly to the throttle valve so as to oscillate therewith.

The flow of fuel into the float chamber IOI is controlled by the float I05 in the usual way so that a -predetermined level of fuel is maintained" in the float chamber at all times. The pipe II5 which is used to supply fuel to the chamber IOI is also used to supply fuel to the idling jet II9 from which the flow of fuel into the mixing chamber H9 is controlled by the throttle I20 in a manner well known to those familiar with the art. When the throttle valve I20 is in the position shown, the air allowed to flow into the mixing chamber II9 from the passageway I25 flows along the walls of tube I22 and in that way draws gas into the mixing chamber III- from the jet II6. On the other hand, when 'the opening of the throttle valve is increased less of the air will flow along the inside surface of the tube I22 and hence less fuel will be drawn from the idling jet I16. v In fact, when the throttle valve is wide open this jet may be designed to be substantially inoperative since the fuel required for combustion will then be supplied by the venturi I04 and the high speed Jet I50.

As the throttle valve I20 is moved to accelerate the engine the venturi is brought more into play III.

The pump mechanism comprising the piston and the cylinder I99 operate to deliver an accelerating charge of fuel into the mixing chamber III through the let I59 whenever the-throttle valve is quickly moved to a wide open position in exactly the same way as the pumping mechanism in my preferred form of carburetor operates. Similarly, when the throttle valve is quickly moved to a closed position the pump mechanism will exert a decelerating effect in exactly the same way as the pump mechanism of my preferred form of carburetor operates.

Attention is directed to the fact, however, that the return of the piston I40 to its uppermost position in the cylinder I29 is accomplished by the throttle valve itself due to the fact that the guide rod I96 is connected directly to the throttle valve. This arrangement eliminates the necessity for the use of a spring such as the spring 99 of my other form of this invention. Also, it will be observed that as the throttle valve I20 is actuated the cylinder I39 will pivot back and {(5th about its pivotal mounting at the bracket Now, .I desire it understood that although I have illustrated and described in detail the preferred forms of my invention, the invention is not to be thus limited but only insofar as defined by the scope and spirit of the appended claims.

I claim as myinvention:

1. In combination with a carburetor including a fuel discharge passageway for supplying fuel during normal high speeds and a throttle, an accelerating and decelerating device comprising auxiliary fuel pumping means in direct communication with said passageway for receiving a charge of fuel therefrom, and a connection between said pumping means and throttle for restraining fuel pumpingmovementof said pumping means while the throttle is closed and for automatically releasing said pumping means for a fuel pumping operation when said throttle is opened to allow said pumping means to pump fuel independently of said throttle to discharge an accelerating charge of fuel into said passageway, said pumping means being arranged upon a closing movement of said throttle to receive its charge of fuel from said passageway to give a decelerating eflect by temporarily withdrawing the fuel from said pa'sthrottle is closed and for automatically releasing to deliver vapor into the mixing chamber 0. That is to say, the air flowing into the tube I22will then suck a greater amount of vapor from the surface of the heated fuel in the float chambersaid pumping means for a fuel pumping operation to allow it to pump fuel independently of said throttle to discharge an accelerating charge of fuel into said passageway, said pumping means including a spring urged'piston, a guide member upon which said piston is mounted and a connection between the piston and said member for allowing said piston to move on said member.

3. In combination with a carburetor including a throttle, an accelerating device associated with said carburetor and including a cylinder, a cylindrical element movable in said cylinder and a guide member upon which said element is bodily 75 movable, and a connection between said cylindrical element and throttle for restraining fuel pumping movement of said cylindrical element while the throttle is closed and for automatically releasing said cylindrical element for a fuel pumping operation to allow it, to pump fuel independently of said throttle to discharge an accelerating charge of fuel into the fuel discharge of the carburetor.

4. In combination with a carburetor including a throttle, an accelerating device comprising auxiliary fuel pumping means connected to said carburetor and including a cylinder member and a cylindrical member in said cylinder member and a guide element on which one of said members is bodily movable longitudinally thereof, and a connection between said pumping means and throttle for restraining fuel pumping movement of said pumping means while the throttle is closed and for automatically releasing said pumping means for a fuel pumping operation to allow it to pump fuel independently of said throttle to discharge an accelerating charge of fuel into the fuel discharge of the carburetor.

5. In combination with a carburetor including a fuel discharge passageway and a throttle an accelerating and decelerating device comprising auxiliary fuel pumping means in direct communication with said passageway for receiving a charge of fuel therefrom and including a cylinder, a piston therein and a guide member upon which said piston is movable, and a connection between said pumping means and throttle for restraining fuel pumping movement of said pumping means while the throttle is closed and for automatically releasing said pumping means for a fuel pumping operation when said throttle is opened to allow said pumping means to pump fuel independently of said throttle to discharge an accelerating charge of fuel into said passageway, said cylinder of said pumping means being connected directly to said passageway so that upon a closing movement of the throttle said pumping means will draw a charge of fuel directly from said passageway into said cylinder to give a decelerating effect.

6. In combination with a throttle controlled carburetor an accelerating device comprising auxiliary fuel pumping means including a chamber and a recipro'cable spring urged piston therein, a connection between said throttle and said pumping means for controlling the operation of the same, and means for enabling said piston to operate independently of said throttle upon the opening of the throttle including a guide member upon which said piston is movable whereby fuel is discharged from the pumping means to the carburetor immediately after the throttle is opened, said connection including a cam connected to said throttle for depressing said guide member.

7. In combination with a carburetor including a throttle, an accelerating device comprising auxiliary fuel pumping means connected to said carburetor and including a cylinder member and a cylindrical member in said cylinder member, a guide element on which one of said members is bodily movable longitudinally thereof and resilient means for returning said movable member to its original or starting position after each operation thereof, and a connection between said pumping means and throttle for restraining fuel pumping movement of said pumping means while the throttle is closed and for automatically releasing said pumping means for a fuel pumping operation to allow it to pump fuel independently of said throttle to discharge an accelerating charge of fuel into the fuel discharge of the carburetor.

8. In combination with a carburetor-including a high speed discharge nozzle for supplying fuel during normal high speeds and a throttle, an accelerating device disposed in a direct communication with said discharge nozzle but arranged so as not to interfere with the normal discharge of said nozzle and comprising spring operated fuel pumping means and means actuated by the throttle for storing energy in the spring during the closure of the throttle and means for disconnecting the pumping means from the throttle on opening the throttle whereby fuel is gradually discharged from the pumping means directly into said high speed nozzle immediately after the throttle is opened to augment the fuel discharge of said nozzle.

9. In combination with a carburetor including a high speed discharge nozzle for supplying fuel during normal high speeds and a throttle, accelerating means disposed in direct communication with said discharge nozzle comprising a spring operated pumping means, means actuated by the throttle for compressing the spring of said pumping means, and means for releasing the compressed spring when the throttle is quickly opened whereby the spring pumping means gradually discharges fuel directly into said high speed nozzle under the action of said compressed spring to augment the fuel discharge of said nozzle.

10. In combination with a carburetor including a throttle, an accelerating device associated with said carburetor and including a cylinder, a cylindrical member movable therein, a guide member on which said cylindrical member is bodily movable in said cylinder, a spring for enabling said cylindrical member to move on said guide member independently of the movement of said throttle, and means for returning said cylindrical member to its original or starting position after each operation thereof, said means including a connection between said pumping means and throttle for restraining fuel pumping movement of said pumping means while the throttle is closed and for automatically releasing said pumping means for a fuel pumping operation to allow 'it to pump fuel independently of said throttle to discharge an accelerating charge of fuel into the fuel discharge of the carburetor.

11. In combination with a throttle controlled carburetor an accelerating device comprising auxiliary uel pumping means including a chamber and a reciprocable spriig urged piston therein, a connection between said throttle and said pumping means for controlling the operation of the same comprising a shaft having means connected thereto for setting said pumping means into action, and linkage between said throttle and said shaft for enabling them to be operated together, and means for enabling said piston to operate independently of said throttle upon the opening of the throttle including a guide member upon which said piston is movable whereby fuel is discharged from the pumping means to the carburetor immediately after the throttle is opened.

12. In combination with a throttle controlled carburetor an accelerating device comprising auxiliary fuel pumping means including a chamber and a reciprocable spring urged piston therein, a connection between said throttle and said pumping means for controlling the operation of the same, and means for enabling said piston to operate independently of said throttle upon the opening of the throttle including a guide member upon which said piston is movable whereby fuel is discharged from the pumping means to the carburetor immediately after the throttle is opened. said guide member having anond thereof provided with an enlargement for normally holding the piston against displacement and adapted to limit the independent movement of said piston.

13. In a carburetor a fuel discharge passageway. a throttle valve in said passageway, float chambers, an idling ,iet connected to one of said chambers to discharge in said passageway adjacent said throttle valve, a high speed discharge Jet connected to another of said chambers and arranged to discharge fuel into said passageway and an accelerating device comprising fuel pumping means connected and operable with said throttle valve and disposed in direct communication with said high speed lot so as to receive its charge of fuel from said Jet and to discharge said charge into said jet upon the quick opening of said throttle.

14. In combination with a throttle controlled carburetor an accelerating device comprising auxiliary fuel pumping means including a chamber and a reciprocable spring urged piston therein, a connection between said throttle and said pumping means for controlling the operation of the same, and means for enabling said piston to operate independently of said throttle upon the opening of the throttle including a guide member upon which said piston is movable and a connection between said member and piston for allowing said piston to move on said member whereby fuel is discharged from the pumping means to the carburetor immediately after the throttle is opened, and entirely independent of the movement of the throttle so that no substantial pumping of fuel is effected on the opening movement of the throttle in itself, said pumping of the fuel being caused primarily by the independent movement of said spring-urged piston after the. opening of the throttle.

15. In combination with a carburetor including a fuel discharge passageway for supplying fuel during normal high speeds and a throttle, an accelerating and decelerating device comprising auxiliary fuel pumping means in direct communication with said passageway for receiving a charge of fuel therefrom, and a connection between said pumping means and throttle for restraining fuel pumping movement of said pumping means while the throttle is closed and for automatically releasing said pumping means for a fuel pumping operation when said throttle is opened to allow said pumping means to pump fuel independently of said throttle to discharge an accelerating charge of fuel into said passageway, said pumping means-being arranged upon a closing movement of said throttle to receive its charge of fuel from said passageway to give a decelerating effect by temporarily withdrawing the fuel from said passageway, said connection between said throttle and pumping means causing substantially all of the fuel pumped to be dependent upon actuation of the opening movement of the throttle but in a manner that there is no substantial hydraulic resistance to the opening of the throttle.

16. In combination with a carburetor including a fuel discharge passageway and a throttle. an accelerating device comprising auxiliary fuel pumping means in direct communication with said passageway for receiving a charge of fuel therefrom, and a connection between said pumping means and throttle for restraining fuel pumping movement of said pumping means while the throttle is closed and for automatically releasing said pumping means for a fuel pumping operation to allow it to pump fuel independently of said throttle to discharge an accelerating charge of fuel into said passageway, said pumping means including a spring urged piston, a guide member upon which said piston is mounted and a connection between the piston and said member for allowing said piston to move on said member, the movement of said throttle in itself being ineffective to pump fuel so that there is no substantial hydraulic resistance to the opening of the .throttleand the pumping of the fuel by said pumping means follows as a result of such opening movement but is not motivated thereby.

' 1'2. In combination with a carburetor including a throttle, an accelerating device associated with said carburetor and including a cylinder, a cylindrical element movable in said cylinder and a guide member upon which said element is bodily movable, and a connection between said cylindrical element and throttle for restraining fuel pumping movement of said cylindrical element while the throttle is closed and for automatically releasing said'cylindrical element for a fuel pumping operation to allow it to pump fuel independently of said throttle to discharge an accelerating charge of fuel into the fuel discharge of the carburetor, said pumping means being effective to pump fuel entirely independently of the force expended in the movement of the throttle so as to not cause the fuel being pumped to resist movement of the throttle.

HERMAN V. CROON. 

